When "Bill Nye the Science Guy" went on the air in 1993, one of the smartest smartphones around was an $899 brick-sized contraption called the Simon Personal Communicator. Today, Simon is ancient history — but Bill Nye's smarts are still circulating, on video, on the Web, and now on the latest generation of smartphones and tablets.

The Bill Nye the Science Guy app — introduced this month by Disney for iPhone, iPod Touch and iPad — celebrates the 20th anniversary of Nye's premiere by offering clips from some of his shows, a gaggle of games with space and science themes, a virtual Martian sundial, six experiments to do at home, and even instructions for tying his signature bow tie.

It's been a long, strange trip for the former Boeing engineer, who first struck a chord on TV with a mad-scientist gig on Seattle radio and TV stations. That led to the children's show that bore his name, followed by a science show for grownups called "The Eyes of Nye," followed by his service as the nonprofit Planetary Society's chief executive officer. Today, he has the kind of science celebrity status that Mr. Wizard, a.k.a. Don Herbert, had for an earlier generation.

Nye, 57, says he's honored by the comparisons to Mr. Wizard.

"Don Herbert, Mr. Wizard, sent mankind to the moon," Nye told NBC News. "Many of the young engineers who went to work at NASA in the 1960s were inspired by Mr. Wizard in the 1950s. I studied Mr. Wizard episodes. ... If I'm really carrying the torch of Don Herbert, that's a pretty worthy life right there."

"I say to the grownups, if you want to deny evolution and live in your world, in your world that's completely inconsistent with everything we observe in the universe, that's fine," Nye said last year in a widely watched BigThink video. "But don't make your kids do it, because we need them. We need scientifically literate voters and taxpayers for the future."

In an interview scheduled to promote the release of his app, Nye reflected on topics ranging from the future of the space effort to those crazy bow ties:

On the show's longevity:"It's just amazing to me that 20 years later, people are still using the show in classrooms. The show still has value. I went to see Carl Sagan [the late astronomer who was one of Nye's professors at Cornell], and he said, 'Focus on pure science. Don't mess with technology. Kids resonate pure science.' It was good advice."

On the keys to better education in science, technology, engineering and math (STEM):"What I believe right now, based on a very compelling study done at Michigan State University by Jon Miller, is that algebra is the turning point. The single biggest indicator for whether or not a person will pursue a career in math, science or engineering is not science education per se. It's actually algebra. So I believe that algebra is not expensive to teach. We just have to adjust our curriculum a little bit, so that people are using symbols to represent numbers earlier in their school career."

On experiments he hasn't done that he still wants to do:"I like blowing things up, but that's not my main thing. Anytime you get something falling a long way or shooting up a long way, that's pretty good. Who doesn't want to build his own rocket? One thing that does interest me, I gotta say, there's Virgin Galactic and there's a company called XCOR with the Lynx rocket plane. ... That really intrigues me, going into space for a few minutes."

On the future of the space effort:"What we advocate is $1.5 billion for planetary science, and the other thing we advocate is the Decadal Survey. The Decadal Survey was produced by the National Research Council. They got scientists and engineers together, and they met and they met and they met for two years, and they argued, and they said, 'Here's what we want to do: We want to bring back a sample from Mars, and we want a mission to Europa.' ... Human spaceflight does not have the equivalent of a Decadal Survey. In my opinion, that's their problem. In human spaceflight, you've got to be thinking about decades, not a single decade. It is a hard, hard business."

On the reason why Mars is the main target of space exploration:"What we want to do is get a person to Mars for the sake of exploration, because there are two questions that get everybody: Where did we come from? And are we alone? If you say you don't ask those questions, I don't believe you. To answer those questions, you've got to explore space, and the next logical place to look for life is Mars. You could say it's Europa, and we say yes, yes, yes, the Planetary Society is kooky for Europa. We want to put a boat on Titan. Yes, cool. But humans on Mars has got to be the goal, and there has to be something equivalent to the Decadal Survey. We have to get people in Congress, and the Office of Management and Budget, and NASA ... Everybody's got to get together and not get off on 'Let's land on the moon,' or 'Let's drag an asteroid beyond the moon.'

On the origin of Bill Nye's bow-tie fashion statement:"When I was in high school, by long tradition, the boys wait on the girls at the girls' athletic banquet. ... So I said to my colleagues, 'OK, guys, if we're going to be waiters, let's really dress like waiters. Let's impress the ladies.' So my father, who's very skilled with knots, showed me how to tie a bow tie. And I got ... well, I won't say obsessed, but I became quite interested in bow ties. I remember practicing tying the tie over and over again around my leg — your thigh is about the same diameter as your neck, at least for most people. It became a thing. I have several hundred bow ties now. The Smithsonian — the Smith-freakin'-sonian — wants my ties."